Classification
100 - Philosophy & psychology
300 - Social sciences
3
000 - Computer science, information & general works
2
200 - Religion
2
320 - Political science
2
330 - Economics
2
333 - Economics of land & energy
2
500 - Natural sciences & mathematics
2
140 - Specific philosophical schools
1
170 - Ethics
1
370 - Education
1
600 - Technology
1